Northern San Juan
AvalancheSean Zimmerman-Wall · Feb 7, 2020 · Northern San Juan
Weather
Seemed like the area around RMP was in a micro climate of prolonged stormy conditions. Continued snowfall all day, moderate accumulations on skin tracks, primarily due to wind. Temps were reasonable, but wind out of the northwest was bothersome, even BTL. Visibility was greatly reduced due to blowing snow. A very brief lull near mid afternoon occurred over RMP, but it was short lived and the sun never appeared.
Snowpack
Storm snow had a much different character than on Thursday. The latest storm snow was upside down and trailbreaking was difficult. Our AIARE PRO 1 students targeted previously noted fragile snowpack structure on SE-S-SW aspects near and below treeline. This latest crust/facet sandwich developed on 2/2 and has been loaded with nearly 2 feet of storm snow since 2/5 PM. Although storm snow instabilities 6-12" deep were noted in snowpack tests, the most staggering results were sudden collapsing and propagation in multiple large column tests (PST and ECT) on this poor structure. Deeper layers that were previously active in late January did not show propensity for propagation. It appears that new avalanches could fail up to 2 feet deep BTL, but likely more where the wind slab is a contributing factor to this issue.
Avalanche
No avalanches were observed today, but travel was confined to BTL due to wind, snow, and group size.